Traditionally, dedicated access networks have been used to provide dedicated services. For example, cable networks would provide television services, telephone networks would provide telephone services, and data networks would provide data services. With the rapid acceptance and expansion of packet-based technologies, there is a movement toward providing disparate services over a common packet network.
While significant progress has been made to provide core networks capable of transporting packets for various services, access networks connecting to a subscriber's residence or place of business are still relatively separate. Although data services may be overlaid on telephony access networks, these access networks are not configured to support a wide range of simultaneous services such as telephony, video and multimedia. Further, there is little control over the various types of media provided via the data services.
As these media services mature, there will be a need to support voice, audio, video, and other real-time or streaming applications where timely delivery of packets is important over a common access network. Any access network providing a connection to the subscriber premises is likely to have limited bandwidth with respect to the number of services that are available and contending for that limited bandwidth. Given the movement to provide multiple services over a single access network and the different quality of service requirements associated with these services, there is a need for a technique to control the allocation of resources for individual services and assure that subscribers are provided with the resources to which they subscribe while not being allowed access to resources to which they are not entitled.
Service providers are also struggling to use the access networks efficiently by maximizing use of available network resources. Such efficiency is difficult when faced with allocating resources for different types of services, which often require different performance requirements. In particular, different types of services generally result in packets of significantly different lengths and having different transmission priority. As the finite capacity of the access network is approached, routing packets of different lengths with different transmission priorities becomes more difficult, if not impossible. For real-time traffic, such as voice or streaming audio and video sessions, concurrent processing of relatively long packets for a data session may significant impact the ability to timely deliver the real time traffic. For example, time-sensitive real time traffic packets may be delayed while transmitting an excessively long data packet, which is not time-sensitive. If all of the packets for the various sessions were of a relatively similar length, or at least were not excessive in length, resource allocation and prioritization could be better managed.